Affiliation: | 1.School of Mathematical Sciences, Xiamen University, Xiamen, 361005, Fujian, China ;2.Department of Mathematics and Statistics, Oakland University, Rochester, MI, 48309, USA ;3.Department of Mathematics, Qinghai Normal University, Xining, 810008, Qinghai, China ;4.School of Computer, Qinghai Normal University, Xining, 810008, Qinghai, China ;5.Academy of Plateau Science and Sustainability, Xining, 810008, Qinghai, China ; |